Merge tag 'locking-urgent-2025-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc locking fixes from Ingo Molnar:

 - Restrict the Rust runtime from unintended access to dynamically
   allocated LockClassKeys

 - KernelDoc annotation fix

 - Fix a lock ordering bug in semaphore::up(), related to trying to
   printk() and wake up the console within critical sections

* tag 'locking-urgent-2025-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/semaphore: Use wake_q to wake up processes outside lock critical section
  locking/rtmutex: Use the 'struct' keyword in kernel-doc comment
  rust: lockdep: Remove support for dynamically allocated LockClassKeys

1 files changed, 4 insertions, 12 deletions

diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index 3498fb344dc9..16eab9138b2b 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -30,28 +30,20 @@ pub struct LockClassKey(Opaque<bindings::lock_class_key>);
 unsafe impl Sync for LockClassKey {}
 
 impl LockClassKey {
-    /// Creates a new lock class key.
-    pub const fn new() -> Self {
-        Self(Opaque::uninit())
-    }
-
     pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key {
         self.0.get()
     }
 }
 
-impl Default for LockClassKey {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
 /// Defines a new static lock class and returns a pointer to it.
 #[doc(hidden)]
 #[macro_export]
 macro_rules! static_lock_class {
     () => {{
-        static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new();
+        static CLASS: $crate::sync::LockClassKey =
+            // SAFETY: lockdep expects uninitialized memory when it's handed a statically allocated
+            // lock_class_key
+            unsafe { ::core::mem::MaybeUninit::uninit().assume_init() };
         &CLASS
     }};
 }